Apparatus for concentrating sulphuric acid



(No Model.)

P. W. KALBPLEISOH. APPARATUS FOR GO'NOENTRATING SULPHURIG A011).

No. 2 7,221. Patented Nov. 7, 1882.

WITNESSES 4/ INVENTOR da- Wfw/Qm ATTORNEY N PETERS. Pmwmrm n her, Walkman)". u. c.

NITED STATES PATENT OFFICE.

FREDERICK W. KALBFLEISOH, OF BROOKLYN, NEIV YORK.

APPARATUS FOR CONCENTRATING SULPHURIC ACID.

SPECIFICATION forming part of Letters Patent No. 267,221, dated November 7, 1882.

Application filed April 24, 1882.

specification.

My invention comprises, first, a contrivance whereby the apparatus for heating and partly concentrating the acid preparatory to entering the still is enabled to be constructed cheaper, and is calculated to be more durable, and also more economical of the heat used; second, a

more economical construction of the platina still, both in respect to a saving of the expense of material of which the still is made and in the effectiveness of the still third, a more economical method of supplying the steam required in the leaden chambers; and, fourth, elevating the condenser, so that the condensed vapors from the still flow directly into the chamber, thus dispensing with pumping,which is the method usually employed to return the condensed vapors back into the chamber.

Figure l is a longitudinal sectional elevation of my improved apparatus. Fig. 2 is a top view without the generating-chamber. Fig. 3 is a longitudinal section of the still, and Fig. 4 is a transverse section.

For the preparatory process I make a flat steam-box, A--say three feet wide by six feet longand two or three inches deep-the bottom and side being preferably of boiler-iron and the top of steel,the latter to enable the heat to passmorereadilythanitcan through thethieker iron. On the top of this box, which may be set in asbestos, cement, or any other approved non-conductor of heat, I lay a shallow pan, B, ofsheet-lead, platina, or any other suitable material. Atthe back of this pan, and elevated somewhat above it, I place a leaden pan or box, 0, open at the top and five or six inches deep, and of the same width as the shallow pan B,

and in it, near the discharging side D, is a partition, E, extending from the top nearly to the bottom, and parallel with the side over which the acid flows, said side being a little lower than the others, and having a chute or apron, F, over which the acid flows into the shallow pan B. At the back of the partition E, I arrange a horizontal coil, G, of lead pipe, elevated somewhat above the bottom of the (No model.) Patented in England April 25,1877, No. 1,618.

discharging end, from which end it rises gradually toward the receiving end, and forms the dome, with capital V and beak \V thereat for conducting the vapors into a condenser, K, usually employed with concentrating apparatus, which condenser I elevate sufiiciently high, as shown in Fig. 1, so that the condensed vapors flow back directly into the leaden chamber B, said beak being extended vertically from the still to said condenser and above the bottom of chamber H. The interior of this still, which should be two or three inches deep, I divide by soldering to its sides, and also to its bottom, at intervals, one or more plates, L, of platina, traversing it from side to side and set edgewise to the bottom, said plate or plates being so arranged that they reach nearly to the bottom, except at intervals, where they touch and are soldered thereto. The plate or plates are employed for two purposes-first, to strengthen the bottom of the still, which, on account of the great expenseof the material, it is desirable to make as thin as possible,-and, second, to compel only the strongest acid (which by reason of its greater specific gravity settles to the bottom) to flow uniformly over the same, and to occupy the successive divisions, so that at the last division only the strongest and most concentrated acid will run ott' at the discharge-pipe M. By the employment of these plates in the manner described to support the bottom of the still I avoid the use of supporting-bars or othersupports under the bottom, which would occupy considerable area of the bottom surface of the still and lessen the effect of the heat thereon, and I also avoid exposure of the supports to the heat, so as not to be injured thereby.

For regulating the depth of acid retained in the still I make the discharge-pipe with an arched section, N, and connect it to the still, so that it can be shifted around to elevate or depress said section, and thus make the passage over which the acid escapes higher or lower, as the case requires. is the inletpipe for the acid, which is diagonally opposite to the outlet'pipe M, thus insuring the best results in respect to the application of the heat to the acid in the still, and also enabling another still to be connected thereto, should occasion require. The still is placed on a steambox, B, which is similar to the steam-box A, the same being connected by a pipe, Q, with the steam-boiler S, and which is also connected with the box A by the pipe R, and under this steam-box P may be a furnace, T, forsu; perheating the steam in it.

In using the apparatus sufficient acid is run from the leaden chamber into the pan or box 0 to fill it and to cover the bottom of the shal low pan B and the bottom of the still I. Then the steam is let into the superheater S and a fire lighted in the furnace under the box P. From the superheater S the steam is conveyed into the box P, passing thence into the steambox A, thence through the leaden coil of pipe G in the leaden pan or box 0, and finally it discharges into the leaden chamber H, where, after being cooled in the leaden pan or box 0 by giving oft its heat to the acid, and thus producing a useful effect by cooling, supplies the aqueous vapor required for generating the acid in the leaden chamber cheaper than when made especially for that purpose, as in the ordinary method. The acid which is first heated in the pan 0 passes down under the partition E, which prevents the heavier portion from remaining in the box, and so flows on to the shallow pan B, where it is concentrated to about 60 Baum, and from thence it flows into the still I, where it is concentrated to 66 Baum.

Heretofore the shallow pan B and still I have been placed over furnaces, and the leaden pan, being thus exposed to the fire, is often overheated and melted, as the heat required to concentrate the acid is nearly the same as is required to melt the lead, and, at best, the furnace-heat is irregularly'distributed, whereas by the steam heat the distribution is uniform, according to my herein described arrange- 'ments.

By the contrivance of the dome of the still at the end where the acid enters, and where the greater volume of vapor arises and escapes, and by contracting therefrom toward the other end, two important advantages are gained-via, the volatile matters are more quickly separated from the more concentrated portions, so that the contact of the latter with the former is less as it flows along toward the escape or discharging passage, thus facilitating the separation, and by so tapering the top a considerable economy of material is effected as compared with the ordinary round conical dome-shaped still.

The equal application or distribution of the steam heat to the shallow pan B, together with the facility of maintaining it uniformly at the highest degree of temperature consistent with safety to thelead pan O,permitsa much smaller evaporating-pan to be used than when fire heat is employed.

As compared with the cost of the ordinary apparatus of the same capacity, my apparatus can be made for about one-third of the cost of the other, while it will be much more durable and effective.

The furnace-fire may, if preferred, be used in direct contact with the still I without the steam-box B',in which case the pipe by which the steam is supplied will be attached directly to the box A from the superheater S.

As the steam will be too hot when leaving the steam box B to be used safely under the leaden pan B, air or steam of lower temperature may be introduced into the first-named box, A, along with it, which will afford means for regulating the temperature exactly as required.

- In regard to the form of the still as above described, and the location of the inlet-pipe and the pipe by which thevapors are conducted to the condenser relatively to the still so shaped and to each other, I may state that very considerable advantages are obtained first, because, by the location of the beak or pipe leading to the condenser being directly over the inlet, which is the place where the largest proportion of the vapor rises, the passage of the vapors to the beak is more direct and with less contact with the surface of the still, so that less space is required to carry it ofi, and there is less condensation by surfacecontact; also, what does condense and drops back into the acid falls into what is less concentrated, and is therefore more readily and more concentrated acid passing on to its outlet, which form effects a considerable economy of the very expensive material of which the still is made.

What I claim, and desire to secureby Letters Patent, is-

1. The combination, with the leaden box 0,

evaporating-pan B, and the still I of a sulphuric-acid-concentratin g apparatus arranged in the order described, of the steam-boxes B and Aand the steam-coil G, the same being arranged and connected to the leaden chamber substantially as described.

2. In a sulphuric-acid-concentrating apparatus in which the evaporation is effected by steam heat, the discharge or waste pipe of the heating apparatus connected to the leaden chamber for utilizing the waste steam of said heating apparatus for supplying the aqueous vapor required in the generating-chamber, substantially as described.

3. A platinum still'having the bottom flat and its top convex from side to side,butgradually sloping downward from inlet to outlet ends, and having the inlet for the acid and the.

for the concentrated acid connected at the lowest end, substantially as described.

4. The partition-plates, used for regulating the flow of the acid along the bottom of the still, arranged for supporting the bottom of the stillby being attached at their ends to the sides of the still, and also being attached to the bottom of the still at intervals along their lower edges, substantially as described.

5. In an apparatus for concentrating sulphuric acid, a condenser placed between the still and the lead chamber, said condenserbein g located above the bottom of the generatingchamber to enable the condensed vapors from the still to flow into said chamber, and thereby dispense with pumping the same into the chamber, substantially as described.

6. In a sulphuric-acid concentrating apparatus, a condenser located above the bottom of the generating-chamber, in combination with a still" 20 provided with a vertical beak extending above the bottom of said chamber, all substantially as described.

In witness whereof I have hereunto signed my name in the presence of two subscribing 25' 

